Casting-machine



J. E. BURNS.

CASTING MACHINE.

APPLICATION FILED IIILI( 2. 1919.

1,373,794. Patented Apr. 5,1921,

ATTORNEY STATES JOH EDWARD BURNS, OIF FLUSHING, NEW YORK.

CASTING-MACHINE.

Specification of Letters Patent.

Patented. Apr. 5, 1921.

Application led July 2, 1919. Serial No. 308,285.

T all whom. t may concern Be it knownthat I, JOHN EDWARD BnizNs, a citizen of the UnitedStates, and a resident of Flushing, county of Queens, and State of New York,' have invented certain newand useful Improvements in Casting-Machines` of which the following is a specification, reference being had to the accompanying drawing.

My invention relates to new and useful improvements in casting machines and more especially to such as are used for dental work, and its object is to provide a simple and eflicient apparatus for forming castings under pressure. More specifically its object is to provide an easily controlled device for ythe device, which is made according to and embodying this invention with the parts thereof shown in two of their different relaf tive positions.

Fig. 2 isl a similar view of. some of the arts shownlin Fig. 1 with the parts shown in a third operative position.

Fig. 3 is a sectional view of another form of one of the interchangeable plunger caps. Like characters of reference 4designate corresponding parts in all of the figures of the drawings. desi 'hates a base on which the various parts o mounted. 11 is a frame orbracket affixed to this base and forming a table 12 and two spaced plunger bearing supports 13 and 14. Above the table a link 15 is pivoted to the frame at 16 and to an actuating lever 17 at 18. 20 is a hollow rod which slides vertically in the supports 13 and 14. A collar 21 is fixed to this rod to which collar the lever 17 is pivotally connected at 19. Another collar 22 is slidably supported on the lower.

end of rod 20 to which is fixed a plunger head 23. Thisis internally threade to rethe apparatus are ceive any one of a number of different plun-l ger caps, such as that shown at 24 in Figs. 1 and 2 or that shown at'24a in Fig. 3. 25 1s a valve rod fixed to the collar 22 and extending up through the hollow rod 20 at which upper end is a valve 26.

is a valve casing which forms a valve seat 31, which, with the valve 26 divides the valve casing into two chambers 32 and 33 This valve casing also has a recess 34 which acts as a guide at the upper end of the'valve rod 25. l A tank 40 is divided by a partition 41 into a pressure chamber 42 and a vacuum chamber 43. 44 is a pump connected with these two chambers through check valves 45 and 46, respectively, which are faced opposite so that when the plunger of the pump is actuated air'will be withdrawn from the chamber 43 and forced into the chamber 42. 47 1s a pressure gage on the tank 40. A pipe 48 leads from the pressure tank to an mounted on the bracket 1'1. A fiexible tube 35 leads from the pressure regulating valve to the chamber 32 of valve casing l30. Another flexible pipe 36 leads from the chamber 33 to the inside of the plunger head 23 with which it is connected as at 37 at an angle inclined to the vertical. On the table '12 is a block 50which is connected with the vacuum chamber of the tank 40 by a pipe 51. The end of an exhaust port 52 with which this pipel is connected is controlled by a slidable plunger 53 in which is a port 54. A perforated transverse wall 55 within this plunger is engaged by a conpression spring 56, the other end of which is in engagement with a lower cap 57 'adjustable regulating valve 49, which is screwed into the bottom of the block 50.

The plunger 53 is provided at its lower end with an extending flange 58, which by engaging a shoulder Aformed in block 50 limits4 l port 52.

60 and 61 are two parts of arnolding flask in which is suitable investment material 63, except for the mold cavity 64 which has been left by a pattern of the article which is to be cast. This flask is supported ina cup,

like member 65, the lower end ofwhich forms a hollow boss 66 into which some of the investment material 63 extends, which boss is screwed into the upper end of plunger 53. `67 is a cap for the top of the member 65, the upper part of which forms a hol.

low boss 68, through which the molten metal may be introduced into the chamber 64 through the sprue-hole leading upwardly therefrom. At the bottom of the plunger cap 24 is a gasket 69, which is adapted to be pressed over and to seal the joint between the cup like member 6.5 and its cover 67.

70 is a perforated thimble on the upper end of which is a flange 71 by means of which Ithe thimble is held between the plunger head 23 and the plunger cap 24.

The operation of this device is as follows:

The molding flask is prepared in the usual manner to receive molten metal, after which it is placed in the position in which it is shown in Figs. 1 and 2, while the plunger cap 24 is raised to the'position in which it is shown in dotted lines by 24b in Fig. 1. The molten metal is poured into the flask in the usual way.

Now the piston of pump 44 is actuated until the desired amount of pressure is formed in the chamber 42 and at the same time a partial vacuum will be formed in the chamber 43. The regulating valve 49 is now adjusted to permit air at the desired amount of pressure to be admitted through tube 35 into the chamber 32 of the valve member 30. Now the lever 17 is moved downwardly to ,bring the plunger cap 24 into en agement with the mold flask and its supporting parts and the various parts of the apparatus will then assume the relative positions in which they are shown vin Fig. 1. Further downward movement of the actuating lever 17 will cause a relative movement of the hollow rod 2O and the valve rod 25, which will result in raising the valve 26 from its seat 31. Air under pressure will then be transmitted through tube 36 into the plunger head23 at an angle so that it will not be directly blown through the hollow boss 68 into the spruehole. In order to further diffuse the air blast the thimble 70 is provided. This diffusion is important because of the fact that a direct current of air into the mold cavity would result in disturbing the. molten. metal therein. This air under pressure results in forcing the molten metal into the mold cavity 64 so that a perfect and dense casting results. It' also has a certain cooling effect upon the metal which accelerates the operation.

When the actuating lever 17 is depressed to its fullest extent it will result in pressing the spring 5 vand""L'llw'i'ngtheaplunger 53 to move doffif is shown in/Fig. 2 with its port 54 in a 'inement with its Vexhaust port 52. This will into the position in whi'l'i' itcause air to be'sucked out from the bbttom.

of the flask throughrthe investment mate-f" rial so that if any air pockets have been flask` and cap together',

molding flask herein shown and described nor to the specific use, which has been described, of the apparatus for'dental work.

The invention upon which this application is based is broader than the apparatus which has been shown and described for the purpose of illustrating one of the possible embodiments thereof and I do not intend any limitations other than those imposed by the appended claims.

What I claim is:` i

1. In avcasting machine, the combination of a mold/ing flask open at opposite ends,a source of compressed air, a hollow plunger cap adapted to seal the top of the flask, an inlet valve for admitting air to the plunger cap, means for withdrawing air from'the bottom of the flask, an outlet valve for controlling said air withdrawing means, and movable means for first bringing the said flask and cap together, said means being arranged to have a further movement, inthe same direction imparted to it for actuating theinlet valve, and a still further movement for actuating the outlet valve.

2. In a casting machine 'the combination` of a flask open at opposite ends, a hollow support therefor, from the bottom ofthe flask, an outlet valve for controlliny said air with rawi means, and means or depressing the flas support and thereby actuating said outlet valve. y

3. In a molding machine, the combination of a flask open atopposite ends, a hollow vertically movablev support therefor, a spring for forcing said support upwardly, means for withdrawing air from the bottom of the flask, an outlet valve for controlling said air withdrawing means, 'the support forming a part of said valve, and means for depressmg the support against its spring to open the outlet valve.

4. In a casting machine, the combination of a molding flask open at opposite ends, a

pressed air, a hollow to seal the. top of the flask, an inlet valve for admitting air to the plun er cap, means for withdrawing ail: lfrom the l ottoni of the flask, ari, outlet valve for controlling said air withdrawing means, and means for bringing said depressing they flask /support and thereby actuating the inlet iso' valve and for depressing the ask support and thereby actuating said outlet valve.

5. In a casting machine, the combination of a molding flask open at opposite ends, a hollow vertically movable support therefor, a spring for forcing said support upwardly, a hollow plunger cap adapted vto seal the top of the flask, an inlet valve for admitting air to the plunger cap, means for Withdrawing air from the bottom of the flask, an outlet valve for controlling said air Withdrawing means, the supportforming a part of said valve, movable means for first bringing the said flask and cap together, said means being arranged to have a further movement imparted to it in the same direction for actuating the inlet valve, and a still further movement in the same direction for depressing the support against its spring to open the outlet valve.

In witness whereof, I have hereunto set my hand this 22nd da)T of June, 1919.

JOHN EDWARD BURNS. 

